Wine bottle closures made from natural cork can be a source of chemicals which may produce mouldy taints in the contents of the bottle. These chemicals (such as trichloroanisoles) may originate from the bleaching process used for cork which involves treatment with chlorine or other chloro compounds. Wine which has been exposed to such chemicals is described as being "corked", and it has been estimated that the wine in up to 10% of all bottles of wine sold worldwide may be corked in this manner. Further, cork is becoming an increasingly scarce commodity and is now so expensive that some winemakers have resorted to the use of corks made from agglomerated particles of recycled cork. These so-called "agglo" corks have also been shown to taint wine, probably, in part, as a result of the adhesive used.
Consequently, there is a great need for inexpensive alternatives to cork bottle closures. Two such alternatives are plastic "champagne-style" corks and metal screw-cap "Stelvin" closures. Whilst these types of closures produce an excellent seal, their use has been limited to low grade wines due to their poor aesthetic qualities.
It is now proposed that closures comprising synthetic and/or natural fibres, particularly wool, would be an excellent alternative to cork.